Portable Power Tool

ABSTRACT

The invention relates to a portable power tool having a motor housing ( 1 ) and a separate handle housing ( 3 ) fastened to the motor housing ( 1 ) by means of an elastic vibration damper ( 2 ) and secured thereon in a positive-locking manner. The vibration damper ( 2 ) is composed of a fastening sleeve ( 4 ) assigned to the motor housing ( 1 ), an elastic damping sleeve ( 5 ) coaxially enclosing the fastening sleeve ( 4 ) and a handle holder ( 6 ) likewise coaxially enclosing the fastening sleeve ( 4 ) and the damping sleeve ( 5 ) and assigned to the handle housing ( 3 ). The essentially rigid construction unit consisting of the handle holder ( 6 ) and the handle housing ( 3 ) is secured in a positive-locking manner, with play, directly to the essentially rigid construction unit consisting of the fastening sleeve ( 4 ) and the motor housing ( 1 ).

The invention relates to a portable power tool having a motor housingand a separate handle housing fastened to the motor housing by means ofan elastic vibration damper and secured thereon in a positive-lockingmanner.

Such a power tool is known from WO 2004/039541 A1. In order forvibrations that occur during operation of such a power tool to be keptaway from the handle housing, the said publication proposes a vibrationdamper which comprises a holder on the motor housing side and areceiving plate on the handle housing side, between which holder andreceiving plate an annular damping element is arranged in the axialdirection. The three components of the vibration damper are layered uponone another in the axial direction, and a number of screw-like securingelements extend through them in the axial direction. The receiving plateis secured to the securing elements in a positive-locking manner. Therear handle held on the receiving plate is prevented from becomingdetached from the motor housing in the event of the damping elementbeing damaged.

The aforementioned arrangement requires a substantial structural spacein the axial and radial directions and is of a complicated structure.The soft damping element is unprotected in the circumferential regionand during operation is exposed to the severe ambient conditionsprevailing in that region.

The invention is based on the object of developing a power tool of thegeneric type so as to ensure a damping and securing function with asimplified structure.

This object is achieved by a portable power tool having the features ofclaim 1.

There is proposed for this purpose a portable power tool wherein thevibration damper is constructed from a fastening sleeve assigned to themotor housing, from an elastic damping sleeve which coaxiallyencompasses the fastening sleeve, and from a handle holder whichlikewise coaxially encompasses the fastening sleeve and the dampingsleeve and is assigned to the handle housing. The substantially rigidstructural unit consisting of the handle holder and the handle housingis secured in a positive-locking manner, with play, directly to thesubstantially rigid structural unit consisting of the fastening sleeveand the motor housing. In the case of the proposed coaxial structuraldesign of the vibration damper, the fastening sleeve, the elasticdamping sleeve and the handle holder are layered in the radialdirection, which permits a thin-walled structural design. The fact thatthe substantially rigid structural unit consisting of the handle holderand the handle housing is secured in a positive-locking manner, withplay, to the likewise substantially rigid structural unit consisting ofthe fastening sleeve and the motor housing permits a free, elastic,vibration-damping relative deformation between the two rigid structuralunits, and thereby an effective vibration decoupling. The positivelocking with play secures the handle housing to the motor housingwithout impeding the vibration decoupling. The direct, positive-lockingsecuring system between the two aforementioned structural units makes itpossible to dispense with the use of additional securing elements. Inparticular, the vibration damper does not need to have any geometricadaptation in order to receive such securing elements, which isconducive to reduction of its structural volume. The damping sleeve canbe designed solely from the point of view of the damping effectrequired, without its function being impaired by separate securingelements.

In an advantageous embodiment, the handle housing overlaps the vibrationdamper in an axial direction in the direction of the motor housing, andis secured, with play, directly to the motor housing. In this case, theprotective chain consists of only two elements, namely the handlehousing and the motor housing, whilst all other elements, such as thefastening sleeve, the damping sleeve and the handle holder, have beentaken out of this securing chain. The securing function achieved is notlimited merely to damage in the damping sleeve, but also covers damageon the fastening sleeve or on the handle holder. Furthermore, aprotective function of the vibration damper is achieved owing to thehandle holder being arranged to overlap on the outside. All individualcomponents of the vibration damper are covered outwardly by theoverlapping region of the handle housing. Dirt, moisture, UV radiationor other disadvantageous ambient influences are kept away from thevibration damper.

In a preferred development, the motor housing has, away from thefastening sleeve, a radially outwardly open circumferential groove inwhich there engages, with play, a radially inwardly directed annularflange of the handle housing. A high bearing capacity is achieved by thearrangement of the circumferential groove in the circumferential regionof the motor housing in cooperation with the annular flange. Thefastening sleeve and the annular flange together form a labyrinth seal,which increases the covering protective function for the vibrationdamper.

In a further expedient embodiment, the handle holder has at least oneradially inwardly directed securing projection which engages, with play,in a securing receiver of the fastening sleeve. The position of thehandle housing relative to the motor housing is secured indirectlythrough direct interaction between the handle holder and the fasteningsleeve, whilst the space-saving, coaxial structural arrangement, layeredin the radial direction, is retained. Here, likewise, a direct,immediate positive locking with play is obtained without additionalfastening elements. It is not necessary for the handle housing and themotor housing to interact directly with each other in a securing manner.The vibration damper can be arranged in the form of a ring, with amaximum radius in relation to the longitudinal axis of the appliance, inthe region of the outer contour of the motor housing and the handlehousing. In the case of the coaxial, radially layered structural design,the external sleeve-like handle holder effects a protective functionupon the sensitive damping sleeve.

In a preferred development, the securing projection, together with aradial damping portion of the damping sleeve, is inserted in thesecuring receiver from the outside inwards, the radial damping portionfilling the play between the securing projection and the securingreceiver. Accordingly, the play is not an entirely free play, but a playwhich is permitted by the elastic deformation of the damping portionthat projects radially inwards. Gaps, cavities or the like, in whichdirt could accumulate and prevent movement, are prevented.

In a preferred development, there is provided between the handle holderand the motor housing in the axial direction an in particular extendingaround gap, from which an impact edge of the damping sleeve projectsradially over the contour of the handle holder and of the motor housing.The damping sleeve thereby performs a multiple function. In the regionof the impact edge, the rubber-elastic, soft material of the dampingsleeve reduces the load on the appliance in the case of external impactloads or shock loads. The anti-slip, haptic characteristics of thedamper material increase the grip of the appliance housing. At the sametime, the impact edge also acts as a seal in the extending around gapbetween the motor housing and the handle housing, such that penetrationof dirt and moisture is prevented in an effective manner. Alternatively,or additionally, it is also possible to provide an impact edge whichprojects over the contour of the handle holder, is arranged on theoutside of the handle holder and, in particular, is realized so as toconstitute a single piece with the damping sleeve and to be materiallyhomogeneous therewith, which impact edge is conducive to improving thegrip and preventing impact stresses.

In an expedient development, the damping sleeve has an axial dampingportion, which is located in the axial direction between an end face ofthe handle holder and an end face assigned to the motor housing. Inaddition to the coaxially and radially layered portion of the vibrationdamper, which is subjected primarily to shearing stress duringoperation, there is also created a portion which is subjected to tensileand compressive stresses. An increased number of degrees of freedom isobtained for structural adaptation of the vibration behavior and dampingbehavior.

In an advantageous embodiment, the damping sleeve and the handle holderand/or the damping sleeve and the fastening sleeve are realized in asingle piece, as a two-component injection-molded component. In additionto a reduction of the resource requirement for production and assembly,in particular positional tolerances of the individual components inrelation to each other are avoided. Clearly defined contact surfacesbetween the individual components can be predefined in a structurallyprecise manner, and remain constant over a long operating period becausepenetration by dirt and moisture is avoided. In this case, openings in asleeve portion of the handle holder and/or of the fastening sleeve areexpediently filled by material of the damping sleeve. In addition to anadhesive material connection of the individual components, there is alsoobtained a positive locking which ensures that the individual componentsare permanently fixed in position in relation to each other.

In a preferred embodiment, the structural unit consisting of the handleholder and the damping sleeve is realized in the form of twohalf-shells, which are firmly connected to each other. In particular, ajoint plane of the two half-shells is arranged, in relation to the axialdirection, at an angle, in particular 90°, relative to a joint plane oftwo housing shells of the motor housing. The offset arrangement of thetwo joint planes relative to each other allows the two half-shells to beused also as a connection element for the two housing shells of themotor housing. The assembly resource requirement is reduced. Wornvibration dampers can be replaced through simple replacement of thehalf-shells realized as single parts. Connection of the two half-shellsto each other is expediently realized through screwed connection or byslipping on an outer, circumferential clamping ring.

Exemplary embodiments are described more fully in the following withreference to the drawing, wherein:

FIG. 1 shows, in a partially sectional side view, a portable power toolaccording to the invention, using the example of an angle grinder havinga first embodiment of the vibration damper;

FIG. 2 shows a perspective exploded representation of a housing shell ofthe motor housing according to FIG. 1 in the region of the vibrationdamper adjoining the motor housing;

FIG. 3 shows the detail III according to FIG. 1, with details relatingto the structure of the coaxially constructed and radially layeredvibration damper and of a system, encompassing the vibration damper, fordirectly securing the position of the handle housing to the motorhousing;

FIG. 4 shows an exploded representation of a further exemplaryembodiment of the invention, with a vibration damper in the form of twoseparate half-shells and a positional securing system on the fasteningsleeve assigned to the motor housing;

FIG. 5 shows a longitudinal sectional representation of the arrangementaccording to FIG. 4, with details relating to the interaction of theindividual components in the region of the vibration damper;

FIG. 6 shows a variant of the arrangement according to FIG. 4, withscrew-connected half-shells of the vibration damper;

FIG. 7 shows a sectional representation of the arrangement according toFIG. 6 in the region of the vibration damper, with details of anadditional impact edge formed-on in a single piece.

FIG. 1 shows, using the example of an angle grinder, a partiallysectional side view of a portable power tool according to the invention.Arranged in a motor housing 1 of the power tool is an electric motor,not represented in greater detail, which drives a working tool, forexample a cutting disk 32, via a bevel gear transmission, likewise notrepresented, which is arranged in a transmission housing 30. The cuttingdisk 32 is held on a tool shaft 31 driven in rotation about a rotationalaxis 33, the rotational axis 33 being approximately at right angles to alongitudinal axis 29 of the approximately cylindrical motor housing 1,which here is slightly conical. Arranged on the end face of the motorhousing 1 which is opposite to the transmission housing 30 is a handlehousing 3, which can accommodate various control elements for the drivemotor and constitutes a rear handle of the power tool.

During operation, the drive motor and the cutting disk 32 producevibrations, which are transmitted to the motor housing 1 and componentsmounted thereon. In order to decouple these vibrations from the handlehousing 3, the latter is fastened to the motor housing 1 by means of anelastic vibration damper 2. The rubber-elastic vibration damper 2permits a vibrating relative movement of the motor housing 1 relative tothe handle housing 3. Its elastic resilience is designed in such a waythat the vibrations are transmitted to the handle 3 only after havingbeen substantially reduced. In addition, there is a damping effect ofthe rubber-elastic material used in the vibration damper 2.

The position of the handle housing 3 relative to the motor housing 1defines an axial direction 7 which, in the exemplary embodiment shown,is approximately parallel to the longitudinal axis 29 of the motorhousing 1. The handle housing 3 overlaps the vibration damper 2 in theaxial direction 7, in the direction of the motor housing 1, and issecured, with play, directly to the motor housing 1. Further detailsrelating thereto are explained more fully in connection with FIGS. 2 and3. The play between the handle housing 3 and the motor housing 1permits, on the one hand, a vibration-decoupling relative movementbetween the two aforementioned assemblies. On the other hand, the systemof securing to the motor housing 1 with play prevents the handle housing3 from becoming detached from the motor housing 1 in the event of thevibration damper 2 becoming worn or damaged.

The vibration damper 2 is comparable in its structure to a tube portion,lying in the axial direction 7, which is arranged approximatelycoaxially relative to the longitudinal axis 29 and extends around closeto the circumferential contour of the motor housing 1 and of the handlehousing 3. For this purpose, the vibration damper 2 is constructed froma fastening sleeve 4 assigned to the motor housing 1, an elastic dampingsleeve 5 which coaxially encompasses the fastening sleeve 4, and ahandle holder 6 which is assigned to the handle housing 3 and likewisecoaxially encompasses the fastening sleeve 4 and the damping sleeve 5.The coaxial structure is so selected that the fastening sleeve 4 and thehandle holder 6 with the interposed damping sleeve 5 are layeredradially from the inside outwards. The handle housing 3 is fixedlyconnected to the handle holder 6 and, together with the latter,constitutes a structural unit which is substantially rigid overallrelative to the rubber-elastic resilience of the damping sleeve. Acomparable case applies in respect of the structural unit consisting ofthe motor housing 1 and the fastening unit 4 projecting from the end ofthe motor housing 1, which structural unit is likewise substantiallyrigid relative to the resilience of the damping sleeve 5. Thevibration-decoupling and vibration-damping relative movement between thetwo components is substantially limited to the deformation of thedamping sleeve 5.

Instead of the angle grinder shown here, other comparable portable powertools, in particular having an electric-motor drive, such as powerdrills or the like, can also be provided.

FIG. 2 shows an exploded representation of a single housing shell 26 ofthe motor housing 1 according to FIG. 1, in the region of the vibrationdamper 2. An opposing housing shell, not shown here, is constructedaccording to the same principle so as to be approximatelymirror-symmetrical and, in being assembled with the half-shell 26 shownhere, is completed to form the motor housing 1 with the formed-onvibration damper 2. It can be seen that the fastening sleeve 4 isrealized in a single piece with the motor housing 1. A two-partstructural design may also be expedient.

Arranged between the fastening sleeve 4 and the motor housing 1,relative to the axial direction 7, is a radially outwardly opencircumferential groove 8, which extends around in the form of a circleand which is delimited by an end wall 35 in the axial direction 7towards the motor housing 1 and by an extending around, outer annularflange 34 in the opposing direction towards the fastening sleeve 4.

The handle holder 6 comprises a cylindrical sleeve portion 19, adjoiningthe end face of which, on the side that faces away from the motorhousing 1, is an extending around, outer annular flange 36 which extendsradially outwards. The fastening sleeve 4 and the sleeve portion 19 ofthe handle holder 6 are provided with a number of openings 20, 21.According to the representations according to FIGS. 1 and 3, the dampingsleeve 5, the handle holder 6 and the fastening sleeve 4 are realized ina single piece, as a two-component injection-molded component, thesleeve portion 19 of the handle holder 6 and the fastening sleeve 4being encompassed on both sides in the radial direction by material ofthe damping sleeve 5. During the injection molding process, the materialof the damping sleeve 5 penetrates the openings 20, 21, whereby anintimate, positive-locking connection of the damping sleeve 5 to thefastening sleeve 4 and to the handle holder 6 is produced. Incombination with the motor housing 1 being designed to constitute asingle part with the fastening sleeve 4 and to be materially homogeneoustherewith, the housing shell 26 shown is realized so as to constitute asingle part, as a two-component injection-molded part, with an assignedhalf-shell of the vibration damper 2. It may also be expedient, withappropriate geometric design, for the fastening sleeve 4, the dampingsleeve 5 and the handle holder 6 to be produced as single parts that areseparate from each other.

FIG. 3 shows an enlarged view of the detail III according to FIG. 1,with the motor housing 1 shown in FIG. 2 and the vibration damper 2,likewise shown therein, in the assembled state. According to thisfigure, it can be seen that the damping sleeve 5 is realized with anapproximately S-shaped cross-section, the fastening sleeve 4 beingcompletely encompassed on the inside and outside in the radial directionby the material of the damping sleeve 5. The same also applies to thesleeve portion 19 of the handle holder 6, the greater materialcross-section of the damping sleeve 5 being located between thefastening sleeve 4 and the handle holder 6 in the radial direction inorder to produce the required elastic resilience. The outer annularflange 34 and the sleeve portion 19 of the handle holder 6 have endfaces 18, 17 which face towards each other at a distance and betweenwhich there is located, without play, an axial damping portion 16 of thedamping sleeve 5 which is formed-on in a single piece and which isprovided to absorb compressive stresses running in the axial direction7.

The outer annular flange 36 of the handle holder 6 projects in theradial direction over the material of the damping sleeve 5 and engageswithout play in an inner annular groove 37 of the handle housing 3. Thehandle holder 6 is realized so as to be separate from the handle housing3. Owing to the fact that the outer annular flange 36 engages withoutplay in the inner annular groove 37, a substantially rigid and immovableconnection is produced between the handle housing 3 and the handleholder 6. An embodiment allowing a variable rotational angle position ofthe handle housing 3 relative to the handle holder 6 about thelongitudinal axis 29 shown in FIG. 1 may also be expedient, theinteraction of the outer annular flange 36 and the inner annular groove37 producing a deflection-resistant connection between the handlehousing 3 and the handle holder 6.

It can also be seen from the representation according to FIG. 3 that thevibration damper 2 extends around radially outwards, close to thecircumferential contour of the motor housing 1 and of the handle housing3, and is overlapped on the outside, in the axial direction 7 towardsthe motor housing 1, by a portion of the handle housing 3, which portionis represented in section. Without further mechanical connection of thehandle housing 3 to the vibration damper 2, the handle housing 3, at itsend which faces towards the motor housing 1, on the inside of itscircumferential wall represented in section, carries a radially inwardlydirected, extending around annular flange 9, which engages with freeplay in the circumferential groove 8 of the motor housing 1. The annularflange 9 lies with a radial spacing from the base of the circumferentialgroove 8 and with an axial spacing from, respectively, the end wall 35and the outer annular flange 34. The radially inwardly directed annularflange 9 engages so deeply in the circumferential groove 8, however,that it overlaps with the outer annular flange 34 of the motor housing1, relative to the axial direction 7. The axial and radial play betweenthe annular flange 9 and the circumferential groove 8 permits a freelyvibrating relative movement of the assembly consisting of the motorhousing 1 and the fastening sleeve 4 relative to the assembly consistingof the handle housing 3 and the handle holder 6. In the event of wear,damage or even breakage of the fastening sleeve 4, the damping sleeveand/or the handle holder 6, the handle housing 3 is secured directly tothe motor housing 1 so as to prevent detachment, in that the annularflange 9 engages in a positive-locking manner, with play, in thecircumferential groove 8.

FIG. 4 shows a further exemplary embodiment of the invention, wherein aperspectively represented motor housing 1, corresponding to therepresentation according to FIG. 1, and a vibration damper 2, comprisingtwo half-shells 22, 23, are provided. The motor housing 1 consists oftwo housing shells 26, 27. A parting line 41 denotes a joint plane 25,represented in greater detail in FIG. 5, between the two housing shells26, 27. A respective annular flange 38, 39, projecting radiallyoutwards, is provided on both sides of the fastening sleeve 4 relativeto the axial direction 7. Between the two annular flanges 38, 39, thefastening sleeve 4 is provided, at two diametrically opposite locations,with a securing receiver 11 in the form of a through-opening.

The two half-shells 22, 23 of the vibration damper 2, between whichthere is a joint plane 24, are separate from the motor housing 1. Thetwo half-shells 22, 23 are each realized in a single piece, as atwo-component injection-molded component, separately from the handlehousing 3 (FIG. 1) and from the motor housing 1, and comprisehalf-shells of the damping sleeve 5 and of the handle holder 6. Thedamping sleeve 5 and the handle holder 6 can also be produced separatelyfrom each other in the form of individual half-shells. Both half-shells22, 23 are provided, centrally on their inside, with a respectivesecuring projection 10 which projects radially inwards and which, in theassembled state, engages in the assigned securing receiver 11 of thefastening sleeve 4. In order to firmly connect the two half-shells 22,23 to each other, there is provided an extending around, approximatelycylindrical clamping ring 28 which, in the assembled state, comes to lieon an assigned extending around cylindrical outer face 40 of the twohalf-shells 22, 23.

FIG. 5 shows, in a longitudinal sectional representation, thearrangement according to FIG. 4 in the assembled state. The twodiametrically opposing securing projections 10 of the sleeve-shapedhandle holder 6 are directed radially inwards, and engage from theoutside inwards, with play, in the respectively assigned securingreceiver 11 of the fastening sleeve 4. Here, likewise, a free radial andaxial play between the securing projection 10 and the securing receiver11, comparable to the free play between the annular flange 9 and thecircumferential groove 8 according to FIG. 3, may be expedient.

In the exemplary embodiment shown, the two securing projections 10,together with a radial damping portion of the damping sleeve 5, areguided from the outside inwards through the securing receiver 11. Theradially inwardly projecting damping portion 12 of the damping sleeve 5thereby encompasses the securing projection 10 completely and, togetherwith the latter, projects into the inside of the fastening sleeve 4. Theradial damping portion 12 fills the play between the securing projection10 and the securing receiver 11 and, owing to its elastic resilience,permits a relative movement of the rigid structural unit consisting ofthe motor housing 1 and the fastening sleeve 4 relative to the rigidstructural unit consisting of the handle housing 3 (FIG. 1), not shownhere, and the handle holder 6. The engagement of the securing projection10 in the securing receiver 11, which engagement extends in the radialdirection, produces a positive locking, with play, which, in the eventof failure of the damping sleeve 5, secures the structural unitconsisting of the handle housing 3 (FIG. 1) and the handle holder 6 tothe structural unit consisting of the motor housing 1 and the fasteningsleeve 4 so as to prevent detachment.

Provided between the handle holder 6 and the motor housing 1, relativeto the axial direction 7, there is an extending around gap 13, which isfilled by the material, formed-on in a single piece, of therubber-elastic damping sleeve 5. The material of the damping sleeve 5 inthis case is shaped so as to constitute an extending around impact edge15, of rounded cross-section, which projects over the contour of thehandle holder 6 and of the motor housing 1. Also constituted thereby atthe same time is an axial damping portion 16 of the damping sleeve 5,which damping portion lies in an elastically resilient manner betweenend faces 17, 18 of the motor housing 1 and of the handle holder 6,respectively. In addition to a sealing effect, absorption of compressivestresses acting in the axial direction 7 is also achieved. In addition,the space that is delimited in the axial direction 7 by the two annularflanges 38, 39 and in the radial direction by the circumferential wallof the handle holder 6 and by the fastening sleeve 4 is filled, at leastapproximately completely, by the material of the damping sleeve 5. Inthis case, the two annular flanges 38, 39 are also completelyencompassed by the material of the damping sleeve 5.

It can also be seen from the representation according to FIG. 5 that thejoint plane 24 between the two half-shells 22, 23 of the vibrationdamper 2 is offset, relative to the longitudinal axis 29, by 90°relative to the joint plane 25 between the two housing shells 26, 27 ofthe motor housing 1 that are represented in FIG. 4. Here, the jointplane 25 lies in the plane of the drawing, whereas the joint plane 24 isperpendicular thereto. On the outside, the clamping ring 28 extendsaround the two half-shells 22, 23 of the vibration damper 2 and holdsthem together. Since the two half-shells 22, 23 firmly encompass thefastening sleeve 4 that is formed onto the motor housing 1 in a singlepiece, these half-shells also hold the two housing shells 26, 27 (FIG.4) of the motor housing 1 together in the region of the fastening sleeve4.

Independently of the previously described holding function of thehalf-shells 22, 23, it may also be advantageous, in the embodiment shownhere and also in the further disclosed embodiments, to provide asingle-piece, pot-shaped motor housing 1 (FIG. 1) instead of the twohousing shells 26, 27 (FIG. 4).

An outer face of the clamping ring 28 is approximately in alignment withan outer face of the motor housing 1 and of the handle housing 3 (FIG.1), and can also serve as a gripping surface for the user. For thispurpose, an appropriate surface texturing or non-slip coating of theouter face of the clamping ring 28 may be expedient.

The handle housing 3, which is not shown here but which is representedin FIG. 1, is held on the outer annular flange 36 of the handle holder6, in accordance with the representation according to FIG. 3, but in theaxial direction extends only as far as the clamping ring 28. In thiscase, the two components have at least approximately the samecircumferential contour. The handle housing 3, by means of its innerannular groove 37 (FIG. 3), extends, so as to be rotatable about thelongitudinal axis 29, on the outer annular flange 36 shown here. For thepurpose of locking the selected rotational position, a number of notches45 are formed in the free end face of the handle holder 6.

In the remaining features and references, the exemplary embodimentaccording to FIGS. 4 and 5 corresponds with that according to FIGS. 1 to3.

FIGS. 6 and 7 show a variant of the arrangement according to FIGS. 4 and5, according to which variant a screwed connection of the twohalf-shells 22, 23 to each other is provided. It can be seen from theexploded representation according to FIG. 6 that the two half-shells 22,23 are constructed so as to be rotationally symmetrical relative to eachother, and have a respective hollow pin 42 and a bore 43 on theirmutually facing end faces. In the assembled state, the respective hollowpin 42 engages in the opposing bore 43. A respective screw 44 isintroduced into the two bores 43 tangentially from the outside inwardsand screwed into the hollow pin 42, whereby a firm connection of the twohalf-shells 22, 23 to each other and to the motor housing 1 is produced.

It can also be seen from the longitudinal sectional representationaccording to FIG. 7 that there is provided in the gap 13 between themotor housing 1 and the vibration damper 2, in addition to the impactedge 14, another, further impact edge 15, which is realized toconstitute a single piece with the damping sleeve 5 of the vibrationdamper 2 and to be materially homogeneous therewith. The impact edge 15projects outwards over the contour of the handle holder 6 in the radialdirection and extends around the handle holder 6, on the outside of thecylindrical outer face 40. By means of openings, not shown, in thehandle holder 6, which are filled by the material of the impact edge 15and of the damping sleeve 5, the impact edge is connected to the dampingsleeve 5 in a single piece. In the remaining features and references,the exemplary embodiment according to FIGS. 6 and 7 corresponds withthat according to FIGS. 4 and 5.

1. A portable power tool having a motor housing and a separate handlehousing fastened to the motor housing by means of an elastic vibrationdamper and secured thereon in a positive-locking manner, wherein thevibration damper is constructed from a fastening sleeve assigned to themotor housing, from an elastic damping sleeve which coaxiallyencompasses the fastening sleeve, and from a handle holder whichlikewise coaxially encompasses the fastening sleeve and the dampingsleeve and is assigned to the handle housing, the substantially rigidstructural unit consisting of the handle holder and the handle housingbeing secured in a positive-locking manner, with play, directly to thesubstantially rigid structural unit consisting of the fastening sleeveand the motor housing, the damping sleeve and the handle holder beingrealized as a two-component injection-molded component, separately fromthe handle housing.
 2. The portable power tool as claimed in claim 1,wherein the handle housing overlaps the vibration damper in an axialdirection in the direction of the motor housing, and is secured, withplay, directly to the motor housing.
 3. The portable power tool asclaimed in claim 2, wherein the motor housing has, away from thefastening sleeve, a radially outwardly open circumferential groove inwhich there engages, with play, a radially inwardly directed annularflange of the handle housing.
 4. The portable power tool as claimed inclaim 1, wherein the handle holder has at least one radially inwardlydirected securing projection which engages, with play, in a securingreceiver of the fastening sleeve.
 5. The portable power tool as claimedin claim 4, wherein the securing projection, together with a radialdamping portion of the damping sleeve, is inserted in the securingreceiver from the outside inwards, the radial damping portion fillingthe play between the securing projection and the securing receiver. 6.The portable power tool as claimed in claim 4, wherein there is providedbetween the handle holder and the motor housing in the axial directionan in particular extending around gap, from which an impact edge of thedamping sleeve projects radially over the contour of the handle holderand of the motor housing.
 7. The portable power tool as claimed in claim4, wherein there is provided an impact edge which projects over thecontour of the handle holder, is arranged on the outside of the handleholder and, in particular, is realized so as to constitute a singlepiece with the damping sleeve and to be materially homogeneoustherewith.
 8. The portable power tool as claimed in claim 1, wherein thedamping sleeve has an axial damping portion, which is located in theaxial direction between an end face of the handle holder and an end faceassigned to the motor housing.
 9. The portable power tool as claimed inclaim 1, wherein the damping sleeve and the handle holder are realizedin a single piece, as a two-component injection-molded component,separately from the handle housing.
 10. The portable power tool asclaimed in claim 1, wherein the damping sleeve and the fastening sleeveare realized, in particular together with the motor housing, in a singlepiece, as a 2-component injection-molded component.
 11. The portablepower tool as claimed in claim 9, wherein the damping sleeve, the handleholder and the fastening sleeve are realized in a single piece as a2-component injection-molded component, a sleeve portion of the handleholder and the fastening sleeve being encompassed on both sides in theradial direction by the material of the damping sleeve, and the sleeveportion and the fastening sleeve having openings which are filled by thematerial of the damping sleeve.
 12. The portable power tool as claimedin claim 1, wherein the structural unit consisting of the handle holderand the damping sleeve is realized in the form of two half-shells, whichare firmly connected to each other.
 13. The portable power tool asclaimed in claim 12, wherein a joint plane of the two half-shells isarranged, in relation to the axial direction, at an angle, in particular90°, relative to a joint plane of two housing shells of the motorhousing.
 14. The portable power tool as claimed in claim 12 wherein thetwo half-shells are screwed together.
 15. The portable power tool asclaimed in claim 12, wherein the two half-shells are connected to eachother by an outer, extending around clamping ring.
 16. The portablepower tool as claimed in claim 1, wherein the handle housing isrotatable relative to the handle holder.